Many lighting systems, in particular projectors, typically use discharge lamps as a light source. Recently, some manufacturers have introduced projection systems using LED technology. Such projectors use a combination of red, blue and green LEDs that are combined and projected through an optical system. However, known systems are bulky due to the optical system, and need extensive cooling.
It is an object of the invention to provide an improved optical projection and illumination system. In particular, it is an aim of the invention to provide a compact lighting device capable of a high energy density.